1. Technical Field
The present invention relates to amplifiers in general, and more particularly to a bipolar microwave monolithic wide band amplifier.
2. Discussion
Maturing silicon bipolar and Gallium Arsenide (GaAs) Hetero-Junction Bipolar Technologies have made microwave monolithic integrated circuits (MMIC) common place. A common goal for any monolithic circuit is to use design and fabrication techniques to reduce chip size, increase ease of implementation, and reduce costs in high volume production. These design and fabrication techniques should not compromise performance, and if possible, should improve performance. Conventional microwave feedback designs use a series inductance in a feedback loop of an amplifier to enhance the gain bandwidth of the amplifier. For monolithic designs, these inductors are generally implemented with spiral inductors. The fabrication of spiral inductors on a monolithic chip requires careful modeling, a fairly complicated fabrication process, and large surface areas on the Silicon or Gallium Arsenide wafer. These factors are especially important at low frequencies where the inductor values needed are large. It would be advantageous to remove the spiral inductors from the circuit without sacrificing the increased bandwidth provided by them. Despite the long felt need, it does not appear the prior art has proposed a solution to the problem with the simplicity of the present invention.